Reducing intermodulation distortion for intra-band dual connectivity

ABSTRACT

A radio frequency front end (RFFE) is configured to support dual connectivity communications, in which two different radio access technologies such as 4 th -Generation (4G) Long-Term Evolution (LTE) and 5 th -Generation (5G) New Radio (NR) data connections are used simultaneously for communications between a wireless communication device and respective LTE and NR base stations. In described embodiments, the RFFE uses two power amplifiers to reduce intermodulation distortion (IMD). The two power amplifiers produce output signals for a 4G LTE uplink and a 5G NR uplink, respectively. The RFFE also has a combiner that mixes the output signals to produce a composite output signal representing both LTE and NR data. Bypass switches may be used to configure the RFFE so that it can be used for single conventional 4G LTE communications.

CROSS REFERENCE TO RELATED APPLICATIONS

The present disclosure is a continuation of, and claims priority under35 U.S.C. § 120 to, U.S. patent application Ser. No. 16/034,241, filedJul. 12, 2018, the entire disclosure of which is hereby incorporated byreference in its entirety.

BACKGROUND

Cellular communication devices use various network radio accesstechnologies to communicate wirelessly with geographically distributedbase stations. Long-Term Evolution (LTE) is an example of a widelyimplemented radio access technology used in 4^(th)-Generation (4G)communication systems. New Radio (NR) is a newer radio access technologythat is used in 5^(th)-Generation (5G) communication systems. Standardsfor LTE and NR radio access technologies have been developed by the 3rdGeneration Partnership Project (3GPP) for use by wireless communicationcarriers within cellular communication networks.

A communication protocol defined by the 3GPP, referred to asNon-Standalone (NSA), specifies the simultaneous use of LTE and NR forcommunications between a mobile device and a communication network.Specifically, NSA uses Dual Connectivity (DC), in which a user equipment(UE) uses both LTE and NR carriers for uplink communications withcorresponding 4G and 5G base stations. LTE carriers are used forcontrol-plane messaging and for user-plane communications. NR carrierare used for additional user-plane bandwidth.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical components or features.

FIG. 1 is a block diagram of a portion of a wireless communicationdevice that implements dual connectivity using 4G and 5G air interfaces.

FIG. 2 is a block diagram of an example radio frequency front end (RFFE)that may be used in the device shown in FIG. 1.

FIGS. 3A and 3B are block diagrams showing the RFFE of FIG. 3 with theaddition of bypass switches

FIG. 4 is a block diagram of another example RFFE that may be used inthe device shown in FIG. 1.

FIG. 5 is a flow diagram illustrating an example method of transmittingdata signals using dual connectivity.

FIG. 6 is a flow diagram illustrating an example method of receivingdata signals using dual connectivity.

FIG. 7 is a block diagram of an example mobile communication device.

DETAILED DESCRIPTION

Described herein are components and techniques for processingdual-connectivity radio frequency (RF) signals, such as RF signals thatmight be used for operating in a Non-Standalone mode, wherecommunications use both 4G and 5G radio access technologies. Thecomponents and techniques may be used by or within a wirelesstelecommunication device, for example.

In a described embodiment, uplink data is transmitted using both4^(th)-Generation (4G) radio access technology and 5^(th)-Generation 5Gradio access technology. Long-Term Evolution (LTE) is an example of 4Gradio access technology. New Radio (NR) is an example of 5G radio accesstechnology.

The telecommunication device has a radio frequency front end (RFFE) thatsupports simultaneous LTE and NR communications. However, dualconnectivity such as this can produce significant intermodulationdistortion (IMD), and attempting to mitigate IMD might in some casesinvolve dramatically reducing transmit power, resulting in decreasednetwork coverage. IMD can be especially significant when LTE and NRcarriers are near each other in frequency, such as being within the samefrequency band. This might happen for example, when LTE and NR uplinksare both within the 600 MHz band as is the case for B71+N71 5G DualConnectivity. B71 refers to LTE frequencies within the 600 MHz band. N71refers to NR frequencies in the 600 MHz band.

Although two antennas might theoretically be used to reduce IMD, modernsmartphones are often too small to accommodate two low-band antennas ofsufficient gain. Although some smartphones may have a second antennathat is used for diversity signal reception, the second antennatypically has significantly less gain than the primary antenna and itsuse for dual-connectivity transmission would therefore be relativelyineffective.

In accordance with embodiments described herein, an RFFE such as used ina cellular communication device has two power amplifiers, which produceoutput signals for a 4G LTE uplink and a 5G NR uplink, respectively. Theamplified output signals are combined, resulting in a composite outputsignal representing both LTE and NR data. The composite output signal isconnected to an antenna of the device for transmission.

Combining the signals after separate amplification in this mannerreduces IMD issues, even when using a single antenna. The describedconfigurations may also reduce Maximum Power Reduction (MPR) andAdditional MPR (A-MPR) in certain situations.

Although the techniques are discussed in the context of LTE and NR radioaccess technologies, the techniques described herein may also be usedwith different network types, standards, frequencies, and technologies.The techniques may generally be used for various types of carrieraggregation (CA), in which data represented by multiple RF carriers isaggregated to form a single data stream. For example, certain 4G/LTEsystems may use carrier aggregation and may benefit from the disclosedtechniques.

FIG. 1 illustrates relevant components of a cellular communicationdevice 100 for use in a wireless communication network, such as in acellular communication network. The cellular communication device 100may comprise a mobile device such as a smartphone or other telephonichandset, a tablet computer, a laptop computer, a monitoring device, etc.Alternatively, the cellular communication device 100 may compriseanother type of device, such as a controller, an Internet-of-Things(IoT) device, a home automation component, a wireless access point orhotspot, etc. In some cases, the cellular communication device 100 maybe referred to as a user equipment (UE) or mobile station (MS).

The cellular communication device 100 may be configured to communicatewith the wireless communication network using both 4G and 5G radioaccess technologies. For 4G, the cellular communication device 100supports LTE communications. For 5G, the cellular communication device100 supports NR communications. In some implementations, the cellularcommunication device 100 may support other communication, including butnot limited to, 2G, 3G/EDGE, Wi-Fi, Bluetooth, etc.

The components shown in FIG. 1 may be used to implementDual-Connectivity, for use in a Non-Standalone (NSA) configuration. Whenusing NSA, the cellular communication device 100 simultaneouslyestablishes an LTE carrier and an NR carrier with respective LTE and NRbase stations. The LTE carrier is used for control-plane messaging andfor user-plane communications. The NR carrier is used for additionaluser-plane bandwidth. Dual connectivity such as this may also be usedfor certain types of carrier aggregation such as may be used in LTE orother cellular communication systems.

For purposes of discussion, a 4G or LTE component is a component thatperforms according to the 4G or LTE communications standard. A 4G or LTEsignal or communication is a signal or communication that accords withthe 4G or LTE communications standard. A 5G or NR component is acomponent that performs according to the 5G or NR communicationsstandard. A 5G or NR signal or communication is a signal orcommunication that accords with the 5G or NR communications standard.

The cellular communication device 100 has an internal modem andradio-frequency integrated circuit (RFIC), components that arecollectively referred to as a Modem/RFIC 102, that receive an uplinkdata stream 104 from an application processor 106. The modem processesbaseband signals, and the RFIC converts the baseband signals to RFfrequencies.

The uplink data stream 104 is a digital data stream containing data thatis to be transmitted wirelessly to a cellular communication networkusing NSA dual connectivity. The modem/RFIC 102 produces LTE and NR Txsignals 108 and 110, each of which represents a portion of the uplinkdata stream 104.

The LTE Tx signal 108 may also be referred to as an LTE RF outputsignal, and represents a first portion of the uplink data stream 104 inaccordance with the LTE radio access technology. The NR Tx signal 110may also be referred to as an NR RF output signal, and represents asecond portion of the uplink data stream 104 in accordance with NR radioaccess technology. For purposes of discussion, the portion of the uplinkdata stream 104 that is to be transmitted using LTE radio accesstechnology will be referred to as LTE data. The portion of the uplinkdata stream 104 that is to be transmitted using NR radio accesstechnology will be referred to as NR data.

The cellular communication device 100 has an RF front end (RFFE) 112that performs amplification and filtering of analog RF input and outputsignals, including the LTE Tx signal 108 and the NR Tx signal 110. Inthe illustrated embodiment, the LTE Tx signal 108 and NR Tx signal 110are provided concurrently by the modem/RFID 102 to the RFFE 112, forconcurrent transmission by the RFFE 112.

The RFFE 112 transmits and receives using a single antenna 114. Thecellular communication device 100 may in some cases use one or moredifferent or additional antennas for receiving RF signals.

The RFFE 112 is also configured for simultaneous reception of LTE and NRsignals. An LTE Rx signal 116 and an NR Rx signal 118 are providedconcurrently by the RFFE 112 to the modem/RFIC 102. The LTE Rx signal116 may also be referred to as an LTE RF input signal. The NR Rx signal118 may also be referred to as an NR RF input signal. The LTE Rx signal116 represents data that is being received using LTE radio accesstechnology. The NR Rx signal 118 represents data that is being receivedusing NR radio access technology.

The modem/RFIC 102 converts the RF LTE Rx signal 116 and the RF NR Rxsignal 118 to corresponding digital streams, and combines or aggregatesthe digital streams to produce an aggregated downlink data stream 120that is provided to the application processor 106.

The illustrated components of the cellular communication device 100 mayin some embodiments be implemented by a chipset or system-on-chip (SOC),which may comprise one or more integrated circuits. Components such asthe application processor, the modem, the RFIC, the RFFE, and othercomponents may be distributed or arranged in various ways amongintegrated circuits of the chipset.

FIG. 2 shows an example implementation of an RFFE 200, which may be usedas the RFFE 112 of FIG. 1. The RFFE 200 may be used within a cellular orother wireless communication device for simultaneous LTE and NRcommunications and/or for other types of carrier aggregation or dualconnectivity. In certain embodiments, the RFFE 200 may be used tosupport dual connectivity for non-standalone (NSA) mode in accordancewith 3GPP 5G specifications, particularly when LTE and NR signals havefrequencies that vary from each other by only a small amount.

All signals of FIG. 2, as well as the signals of FIGS. 3A, 3B, and 4,are radio frequency (RF) signals. In some embodiments, LTE and NR signalfrequencies may be within the same frequency band or may otherwise havefrequencies that differ by a relatively small amount. For example, LTEand NR signal frequencies may be within a band of frequencies that aredesignated or regulated for cellular device communications, such as the600 MHz frequency band. In these cases, the LTE and NR signalfrequencies may be adjacent to each other (i.e. there is no separationbetween LTE and NR signal frequencies).

The RFFE 200 has a transmit section 202 and a receive section 204. Thetransmit section 202 has a first low-band power amplifier (LBPA) 206that receives and amplifies the LTE Tx signal 108, also referred toherein as an LTE RF output signal, to produce an amplified LTE RF outputsignal 208. The transmit section 202 has a second LBPA 210 that receivesand amplifies the NR Tx signal 110, also referred to herein as an NR RFoutput signal, to produce an amplified NR RF output signal 212.

The amplified LTE RF output signal 208 and the amplified NR RF outputsignal 212 are received by an RF signal combiner 214, which mixes theamplified LTE and NR RF output signals 208 and 212 to create a compositeRF output signal 216. The combiner 214 may be implemented as a linearcomponent, and therefore introduces little intermodulation distortion(IMD).

The composite RF output signal 216 is received by an RF duplexer 218,which connects the composite RF output signal 216 through an antennaswitch 220 for transmission from the antenna 114. The RF duplexer 218may have filters for various frequencies or frequency bands that aresupported by the RFFE 200, including both transmit and receive filters.

In some embodiments, an antenna tuner may also be used between theduplexer 218 and the antenna 114.

The filter bank 220 and duplexer 118 produce a composite RF input signal222 based on RF signals received at the antenna 114. The duplexer 218connects the composite RF input signal 222 to a signal splitter 224. Thesplitter 224 processes the composite RF input signal 222 to produce anLTE RF input signal 226 and an NR RF input signal 228. Morespecifically, the splitter 224 applies appropriate filters to thecomposite RF input signal to create the LTE RF input signal 226 and theNR RF input signal 228.

A first low-noise amplifier (LNA) 230, referred to herein as an LTE LNA230, amplifies the LTE RF input signal 226 to create the LTE Rx signal116. A second LNA 232, referred to herein as an NR LNA 232, amplifiesthe NR RF input signal 228 to create the NR Rx signal 118. An LNA is anamplifier that amplifies a low-power RF signal without significantlydecreasing its signal-to-noise ratio.

The LTE Rx signal 116 represents data that is received in accordancewith LTE radio access technology. The NR Rx signal 118 represents datathat is received in accordance with NR radio access technology.

Note that FIG. 2 shows components that are most relevant to the topicsdiscussed herein. In implementation, the RFFE 200 may have additionalcomponents and may be configured in different ways.

FIGS. 3A and 3B show another example of the RFFE 200. This example issimilar to the example of FIG. 2, except that RF switches 302 have beenadded to allow reconfiguration of the RFFE 200 for non-dual connectivityoperation. Specifically, the RF switches 302 include first and second RFswitches 302(a) and 302(b) that can be used to selectively bypass thesignal combiner 214 and to provide the amplified LTE RF output signal208 directly to the duplexer 218, rather than the composite RF outputsignal 216, for transmission by the antenna. The RF switches 302 furtherinclude third and fourth RF switches 302(c) and 302(d) that can be usedto selectively bypass the splitter 224 and to provide the composite RFinput signal 222 directly to the first LNA 230. FIG. 3A shows theswitches set to positions for use with NSA communications. FIG. 3B showsthe switches set to positions for LTE, non-NSA communications.

FIG. 4 shows another example implementation of an RFFE 400, which may beused as the RFFE 112 of FIG. 1. The RFFE 400 may be used within acellular or other wireless communication device for simultaneous LTE andNR communications and/or for other types of carrier aggregation or dualconnectivity. In certain embodiments, the RFFE 400 may be used tosupport dual connectivity for NSA mode in accordance with 3GPP 5Gspecifications, particularly when LTE and NR signals have frequenciesthat are within the same frequency band and/or that vary from each otheronly by a small amount.

The RFFE 400 has an LTE section 402 and an NR section 404. The LTEsection 402 has a first low-band power amplifier (LBPA) 406 thatreceives and amplifies the LTE Tx signal 108 to produce an amplified LTERF output signal 408. The LTE section 402 also has a first LNA 410,referred to herein as an LTE LNA 410, that receives and amplifies an LTERF input signal 412 to create the LTE Rx signal 116.

The NR section 404 has a second LBPA 414 that receives and amplifies theNR Tx signal 110 to produce an amplified NR RF output signal 416. The NRsection 404 also has a second LNA 418, referred to herein as an NR LNA418, that receives and amplifies an NR RF input signal 420 to create theNR Rx signal 118.

In the LTE section 402, an LTE duplexer 422 receives the amplified LTERF output signal 408 from the LTE LBPA 406 and provides the LTE RF inputsignal 412 to the LTE LNA 410. In the NR section 404, an NR duplexer 424receives the amplified NR RF output signal 416 from the NR LBPA 414 andprovides the NR RF input signal 420 to the NR LNA 418.

The RFFE 400 has a signal combiner/splitter 426 that provides signals toand receives signals from the antenna 114 through an antenna switch 428.

In operation, the combiner/splitter 426 receives an antenna input signal430 from the antenna 114 and splits the antenna input signal 430 toproduce the LTE RF input signal 412 and the NR RF input signal 420,using appropriately selected frequency filters. The LTE duplexer 422 isconnected to receive the LTE RF input signal 412 and to provide it tothe LTE LNA 410. The NR duplexer 424 is connected to receive the NR RFinput signal 420 and to provide it to the NR LNA 418.

The LTE duplexer 422 receives the amplified LTE RF output signal 408 andprovides it to the combiner/splitter 426. The NR duplexer 424 receivesthe amplified NR RF output signal 416 and provides it to thecombiner/splitter 426. The combiner/splitter 426 mixes the amplified LTERF output signal 408 and the amplified NR RF output signal 416 to createa composite RF antenna output signal 432 for transmission by the antenna114.

The combiner/splitter 426 may include multiple filters and associatedswitches so that appropriate filters can be selected and used withdifferent signal frequencies.

The RFFE 400 may have better RF performance than the RFFE 204 of FIG. 2,at the expense of a higher number of components and additional physicalspace.

FIG. 5 illustrates an example method 500 of transmittingdual-connectivity uplink data. The example method 500 may be performedby a cellular communication device such as a smartphone, and morespecifically by device components such as the modem/RFIC 102 and theRFFE 112 of FIG. 1.

An action 502, which may be performed by a modem or other processingcomponent, comprises receiving an uplink data stream that is to betransmitted by the cellular communication device to one or more wirelessbase stations. The uplink data stream may contain uplink data that is tobe transmitted using both LTE and NR radio access technologies.

An action 506, performed by the modem or other processing component,comprises producing an LTE RF output signal representing a portion ofthe uplink data that is referred to as the LTE data stream. The action506 may, for example, comprise modulating a first signal to representthe LTE data stream in accordance with LTE radio access technology.

An action 508, which may be performed concurrently with the action 506,comprises producing an NR RF output signal representing another portionof the uplink data that is referred to as the NR data stream. The action508 may, for example, comprise modulating a second signal to representthe NR data stream in accordance with NR radio access technology.

In some cases, the LTE and NR RF output signals may have correspondingfrequencies that are within a band of frequencies that are designatedfor cellular device communications, such as the 600 MHz B71 and N71bands.

An action 510, which may be performed by the RFFE, may compriseamplifying the LTE RF output signal to produce an amplified LTE RFoutput signal. An action 512, which may be performed by the RFFE 112concurrently with the action 510, may comprise amplifying the NR RFoutput signal to produce an amplified NR RF output signal.

An action 514, which may be performed by a signal combiner of an RFFE,may comprise combining the amplified LTE and NR RF output signals tocreate a composite RF output signal.

An action 516 comprises providing the composite RF output signal fortransmission by an antenna of the cellular communication device.

FIG. 6 illustrates an example method 600 of processing dual-connectivitydownlink signals. The example method 600 may be performed by componentssuch as the modem/RFIC 102 and the RFFE 112 of FIG. 1.

An action 602, performed by the RFFE, comprises receiving an antennasignal from one or more antennas of a cellular communication device. Thereceived antenna signal represents first downlink data in accordancewith LTE radio access technology and second downlink data in accordancewith NR radio access technology. For example, the received signal maycomprise a composite signal containing both LTE and NR signals.

An action 604 comprises splitting the received antenna signal into anLTE RF input signal that represents LTE downlink data and an NR RF inputsignal that represents NR downlink data. The action 604 may beaccomplished by selecting and using appropriate frequency filters,corresponding respectively to the frequency of the LTE RF input signaland the frequency of the NR RF input signal.

An action 606, which may be performed by a modem or other processingcomponent of the cellular communication device, may comprisedemodulating the LTE RF input signal to produce LTE downlink data. Anaction 608, which may be performed concurrently with the action 606, maycomprise demodulating the NR RF input signal to produce NR downlinkdata.

An action 610, which may be performed by the modem or other processingcomponent of the cellular communication device, may comprise aggregatingthe LTE and NR downlink data to produce a downlink data stream.

FIG. 7 illustrates an example mobile communication device 700 that maybe used to implement the techniques described herein. The method 500 ofFIG. 5 and the method 600 of FIG. 6, for example, may be implemented bya device such as the device 700. The components shown in FIGS. 1, 2, 3A,3B, and/or 4 may be implemented within a device such as the device 700.

FIG. 7 shows only basic, high-level components of the device 700.Generally, the communication device 700 may comprise any of varioustypes of cellular communication devices that are capable of wirelessdata and/or voice communications, including smartphones and other mobiledevices, “Internet-of-Things” (IoT) devices, smarthome devices,computers, wearable devices, entertainment devices, industrial controlequipment, etc. In some environments, the communication device 700 maybe referred to as a user equipment (UE) or mobile station (MS).

The device 700 may include memory 702 and a processor 704. The memory702 may include both volatile memory and non-volatile memory. The memory702 can also be described as non-transitory computer-readable media ormachine-readable storage memory, and may include removable andnon-removable media implemented in any method or technology for storageof information, such as computer executable instructions, datastructures, program modules, or other data. Additionally, in someembodiments the memory 702 may include a SIM (subscriber identitymodule), which is a removable smart card used to identify a user of thedevice 700 to a service provider network.

The memory 702 may include, but is not limited to, RAM, ROM, EEPROM,flash memory or other memory technology, CD-ROM, digital versatile discs(DVD) or other optical storage, magnetic cassettes, magnetic tape,magnetic disk storage or other magnetic storage devices, or any othertangible, physical medium which can be used to store the desiredinformation. The memory 702 may in some cases include storage media usedto transfer or distribute instructions, applications, and/or data. Insome cases, the memory 702 may include data storage that is accessedremotely, such as network-attached storage that the device 700 accessesover some type of data communication network.

The memory 702 stores one or more sets of computer-executableinstructions (e.g., software) such as programs that embody operatinglogic for implementing and/or performing desired functionality of thedevice 700. The instructions may also reside at least partially withinthe processor 704 during execution thereof by the device 700. Generally,the instructions stored in the computer-readable storage media mayinclude various applications 706 that are executed by the processor 704,an operating system (OS) 708 that is also executed by the processor 704,and data 710 associated with the applications 706 and/or the operatingsystem 708.

In some embodiments, the processor(s) 704 is a central processing unit(CPU), a graphics processing unit (GPU), both CPU and GPU, or otherprocessing unit or component known in the art. Furthermore, theprocessor(s) 704 may include any number of processors and/or processingcores. The processor(s) 704 is configured to retrieve and executeinstructions from the memory 702.

The device 700 may include the modem/RFIC 102 and the RFFE 112 of FIG.1, as well as associated and/or supporting components.

The device 700 may have a display 712, which may comprise a liquidcrystal display or any other type of display commonly used in telemobiledevices or other portable devices. For example, the display 712 may be atouch-sensitive display screen, which may also act as an input device orkeypad, such as for providing a soft-key keyboard, navigation buttons,or the like.

The device 700 may have input and output devices 714. These devices mayinclude any sort of output devices known in the art, such as a display(already described as display 712), speakers, a vibrating mechanism, ora tactile feedback mechanism. Output devices may also include ports forone or more peripheral devices, such as headphones, peripheral speakers,or a peripheral display. Input devices may include any sort of inputdevices known in the art. For example, the input devices may include amicrophone, a keyboard/keypad, or a touch-sensitive display (such as thetouch-sensitive display screen described above). A keyboard/keypad maybe a push button numeric dialing pad (such as on a typical telemobiledevice), a multi-key keyboard (such as a conventional QWERTY keyboard),or one or more other types of keys or buttons, and may also include ajoystick-like controller and/or designated navigation buttons, or thelike.

The device 700 may have various other components that are not shown inFIG. 7.

Although features and/or methodological acts are described above, it isto be understood that the appended claims are not necessarily limited tothose features or acts. Rather, the features and acts described aboveare disclosed as example forms of implementing the claims.

What is claimed is:
 1. A radio frequency (RF) front end for use in acellular communication device, comprising: a signal splitter to separatea received RF input signal from an antenna to produce a first RF inputsignal and a second RF input signal in a dual-connectivity mode, whereinthe first RF input signal represents first downlink data of a downlinkdata stream in accordance with a first radio access technology and thesecond RF input signal represents second downlink data of the downlinkdata stream in accordance with a second radio access technology; a firstamplifier coupled to a first output of the signal splitter; a secondamplifier coupled to a second output of the signal splitter; and one ormore RF switches to selectively send the received RF input signal to thesignal splitter in the dual-connectivity mode and to one of the firstamplifier or the second amplifier in a non-dual-connectivity mode. 2.The radio frequency front end of claim 1, wherein the first radio accesstechnology comprises a 4th-Generation (4G) radio access technology andthe second radio access technology comprises a 5th-Generation (5G) radioaccess technology.
 3. The radio frequency front end of claim 2, whereinthe first RF input signal is a Long-Term Evolution (LTE) signal and thesecond RF input signal is a New Radio (NR) signal.
 4. The radiofrequency front end of claim 1, wherein: the first RF input signal isassociated with a first frequency; the second RF input signal isassociated with a second frequency; and the first frequency and thesecond frequency are within a band of frequencies that are designatedfor cellular device communications in the dual-connectivity mode.
 5. Theradio frequency front end of claim 1, wherein the one or more RFswitches comprises a first RF switch coupled between the antenna and thesignal splitter and a second RF switch coupled between the signalsplitter and one of the first amplifier or the second amplifier.
 6. Theradio frequency front end of claim 1, further comprising a duplexer toconnect a composite RF output signal for transmission by the antenna andto provide the received RF input signal to the signal splitter.
 7. Theradio frequency front end of claim 1, further comprising: a thirdamplifier to amplify a first RF output signal to create a firstamplified RF output signal, wherein the first RF output signalrepresents a first portion of an uplink data in accordance with thefirst radio access technology; and a fourth amplifier to amplify asecond RF output signal to create a second amplified RF output signal,wherein the second RF output signal represents a second portion of theuplink data in accordance with the second radio access technology.
 8. Acellular communication device, comprising: an antenna receiving acomposite radio frequency (RF) input signal comprising a first portionof downlink data communicated according to a first radio accesstechnology and a second portion of the downlink data communicatedaccording to a second radio access technology in a dual-connectivityoperation; baseband-RF circuitry converting the first portion of thedownlink data and the second portion of the downlink data into anaggregated downlink digital stream, and converting an uplink digitalstream into a first RF output signal according to the first radio accesstechnology and a second RF output signal according to the second radioaccess technology; a first amplifier amplifying the first RF outputsignal into a first amplified RF output signal; and a second amplifierseparately amplifying the second RF output signal into a secondamplified RF output signal.
 9. The cellular communication device ofclaim 8, wherein the first radio access technology comprises a4th-Generation (4G) radio access technology and the second radio accesstechnology comprises a 5th-Generation (5G) radio access technology. 10.The cellular communication device of claim 8, wherein: the first RFoutput signal is associated with a first frequency; the second RF outputsignal is associated with a second frequency; and the first frequencyand the second frequency are within a band of frequencies that aredesignated for the dual-connectivity operation.
 11. The cellularcommunication device of claim 8, further comprising a signal combinermixing the first amplified RF output signal and the second amplified RFoutput signal to provide a composite RF output signal for transmissionby the antenna in the dual-connectivity operation, wherein the firstamplified RF output signal represents first uplink data in accordancewith the first radio access technology and the second amplified RFoutput signal represents second uplink data in accordance with thesecond radio access technology.
 12. The cellular communication device ofclaim 11, further comprising a duplexer that (a) provides the compositeRF output signal for transmission by the antenna and (b) receives thecomposite RF input signal from the antenna.
 13. The cellularcommunication device of claim 11, further comprising an RF splitterseparating the composite RF input signal received by the antenna into afirst RF input signal and a second RF input signal, wherein the first RFinput signal represents the first portion of the downlink data inaccordance with the first radio access technology and the second RFinput signal represents the second portion of the downlink data inaccordance with the second radio access technology.
 14. The cellularcommunication device of claim 8, further comprising one or more RFswitches, between the antenna and an RF splitter, selectively bypassingthe RF splitter with the composite RF input signal.
 15. A methodperformed by a cellular communication device, comprising: receiving acomposite radio frequency (RF) input signal comprising a downlink datastream; splitting the composite RF input signal into (a) a first RFinput signal representing a first portion of the downlink data stream inaccordance with a first radio access technology and (b) a second RFinput signal representing a second portion of the downlink data streamin accordance with a second radio access technology; converting thefirst RF input signal and the second RF input signal into an aggregateddownlink data stream at baseband; converting an uplink data stream atbaseband into a first RF output signal in accordance with the firstradio access technology and a second RF output signal at the secondradio access technology; and separately amplifying the first RF outputsignal and the second RF output signal to produce a first amplified RFoutput signal and a second amplified RF output signal.
 16. The method ofclaim 15, wherein: the first RF input signal is associated with a firstfrequency; the second RF input signal is associated with a secondfrequency; and the first frequency and the second frequency are within aband of frequencies that are designated for non-standalone cellulardevice communications.
 17. The method of claim 15, wherein the firstradio access technology comprises a 4th-Generation (4G) radio accesstechnology and the second radio access technology comprises a5th-Generation (5G) radio access technology.
 18. The method of claim 15,wherein the first RF input signal in accordance with the first radioaccess technology is received from a first base station and the secondRF input signal in accordance with the second radio access technology isreceived from a second base station.
 19. The method of claim 15, furthercomprising combining the first amplified RF output signal and the secondamplified RF output signal to create a composite RF output signal. 20.The method of claim 19, further comprising concurrently producing (a)the first RF output signal representing a first portion of the uplinkdata stream and (b) the second RF output signal representing a secondportion of the uplink data stream.